Piston-head



(No Model.) 4 Sheets-Sheet '1;

H. D. GARRETT.

PISTON HEAD.

No. 256,312. ii- Patented Apr. 11,1882.

N, PETERS. Phmn-Lilhogmpber. Washmgbm o. r,

(No Model.) 4 Sheets-Sheet 2.

' H DiGARRETT PISTON HEAD.

No. 256,312 v v P3tenfed Apr.11',188Z.

mwmullml MM N. PETERS. Pholoinlngaphar. wnhingwn, D. C.

(No Model.) 4 Sheets-Shet a. H. D. GARRETT.

PISTON HEAD.

Patented Apr; 11, 1882.

(No Model.) Q 4 Sheets-Sheet 4.

, H. UGARRETT. I

PISTON HEAD.

No. 256,312. Pat entedApr. 11,1882. 4

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' 1 UNITED STATES PATENT OFFICE.

HUGH D. GARRETT, E PHILADELPHIA, PE N YLVANIA;

. PISTON-HEAD.

SPECIFICATION forming part of Letters Patent No. 256,312, dated April 11, 1882. Application filed June 24, 1881. (No model.)

To all whom it may concern:

Be it known that I, HUGH D. GARRETT, a citizen 'of the United States, residing at Philadelphia,in thecounty of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Piston- Heads; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying-drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

My presentinvention.relates to piston-heads for horizontal or inclined'cylinders used in steam, hydraulic, and'other fluid-acting machinery. Y

'My improvement consists in the following construction and arrangement, which will be I hereinafter fully described, and the points of line y 3 of Fig. 1.

novelty therein set forth in the claims.

Figure 1 represents an outside elevation of a piston-head to which my improvements have been applied. Fig.2 represents acentral section through the line wmof Fig. 1. Fig. 3represents a central section taken through the Fig. 4 represents a detail section taken through the line 2 z of Fig.1. Fig. 5 represents a detail top view of the bearing-block in the lower portion of the pistonhead, and Fig. 6 a similar view of one of the upper bearing-blocks. Figs. 7 and S'repre'sent respectively a side elevation and top view of the packing-rings and their adjusting levers and blocks; and Figs. 9 and 10, detail plan views, broken a-Way,of the packing-rings. Fig.

. 11 represents a diagram view designed to illusand it is suitably cored out for reception of the packing-rings and my improved mechanism for centering the piston and automatically setting out the packing in the cylinder.

B B representlevers, which have each three bearing-points, one of which bearing-points is in the lower portion of the head in the block D, anotherin the upper portion of head in blocks E, and the third at an intermehas the cut adjacent to the block.

diate point against bolts 0. The single block I i The blocks E are constructed with similar bearlug-surfaces, and they have bearings for the upper ends of levers B B. These bearings in block D and blocks E E are hinge-joint bearings, and when once the levers B B are in serted respectivelyin them and the blocks and levers put in place the walls of the pistonhead on either side will serve to prevent any lateral displacement, and the inclosing socket will prevent any endwise displacement, while at the same time the levers will have sutfi cient vibratory movementfor the purposes of my invention.

In putting on the packing-rings, which are preferably two in number, 'I cut each ring at the lower periphery of the piston and at the upper periphery in the manner shown in Figs. 7, S, 9, and 10. 1 also insert into each of the bearing blocks E a dowel-pin, f, arranged at one side of the block, so as to project into a suitable opening into thepacking-ring F, which (See Figs. 9 and 10.) These openings for the reception of the dowel-pins f are formed between the cuts in the rings, and serve to give a positive hearing for the levers B to work against when expanding the packing atthe top of the cylinder. The bolts 0 are adjustable in the mannershown, and serve the purpose of centering the piston within the cylinder,' to provide a hearing for each of the levers B against the head,

and also to provide a means, when the packing rings F become worn at the bottom. of the cylinder, for compensating for the wear by so adjusting them as to set the packing farther out from the head. The bolts 0 also are provided with a lock orjam nut, d, and an extensionhead, d, which reaches nearlyto the upper wall of the opening G, into which opening is inserted the wrench for adjusting said bolts when desired. The extension-head d prevents the nut d from falling off the bolt into the cylinder should it by accident work loose.

The bolts 0 of the piston are arrangd at such an angle to each other as'to have a constant tendency to center the piston within the cylinder, and the weight of the piston exerted upon the packing-rin gs through said bolts 0 and the levers B B and blocks D E E serves to expand the packing throughout the circumference of the same. Over one-third of the Weight of the piston is alone exerted to expand the packing in the top of the cylinder through my arrangement of lovers and supports, as will he seen from diagram Fig. 11 and'the following formula, to wit:

Let a be one of the two supporting-points of the piston, (which are the bolts 0 (J b, the center of gyration; c, the extremity of one of the levers B. Let, moreover, w denote the weight of the piston; e the required pressure at c:

y=bg 7tg-hb=ik--hb the arm of the force z=bl, the arm of the required pressure 0". Assuming the radius to be equal to unity, we have 3 170- hb:cos. sin. 12 30=0.86603- 0216443064959. z=bl=-:sin. 57 3053084339. In consequence of the equality of moments we have y-ie z+-11io111.ac; or, neglecting the moment a e arising from frict1on, y=c'x z.

an increased tension to the bearing-blocks E construction is highly desirable, as the packing is adjustable for wear, and all tendency of the piston to stick in the cylinder through de- 3. A piston-head provided with levers, supports, and centering device, substantially as described, whereby the piston is centered in the cylinder and the weight thereof utilized, through said levers, to bear directly against the upper circumference of the packing-rings to expand the same in the upper part of the cylinder.

4. A piston-head having a lever or levers fulcrnmed in the lower portion of the piston and extending into the upper portion so as to rest against the packing at that point, with suitable bearings for the piston against the levers, whereby the weight of the piston is utilized to expand the packing, substantially as set forth.

5. In a solid piston-head, the combination of the levers B, bolts 0, and openings G, substantially as and for the purpose specified.

6. The combination of levers B, bolts 0, and blocks D E, substantially as described.

7. The combination of levers B, bolts 0 and their nuts d, and blocks D E, substantially as described.

8. The combination of levers B, bolts 0, having the extension-heads d, nuts (I, and blocks D E, substantially as described.

In testimony whereof I aiiix my signature in presence of two-witnesses.

HUGH D. GARRETT.

\Vitnesscs:

R. S. REED, ANDREW J. CAMPBELL. 

